The present invention relates to refrigeration devices that have a defrost cycle and more specifically to condensate collection structures for such devices.
Refrigeration devices generally have a refrigeration loop including a compressor, a condenser, an expansion valve, and an evaporator. Typically, frost that is built up on the evaporator is melted by a self-defrosting feature and the condensate is collected in a condensate drain pan or similar container, so that heat or air flowing through the compartment will evaporate the condensate.
During a defrost cycle in a typical refrigerator or freezer unit, the evaporator is heated to melt the frost that has accumulated within the freezer. The condensate drains out of the freezer to a condensate drain pan located in the bottom portion of the refrigerator or freezer. The liquid condensate typically evaporates from the drain is pan before the next defrost cycle. A heat exchange coil disposed in or adjacent to the drain pan usually serves the purpose of evaporating the condensate and removing the superheat from the compressed refrigerant before it is discharged into the motor is compressor casing. The drain pan is typically mounted on the compressor housing in order to promote evaporation of condensate collected in the drain pan.
A number of prior art techniques have been proposed for evaporating collected condensate from the evaporator of a refrigeration device. An early example of such prior art techniques may be found in U.S. Pat. No. 2,626,509 wherein the patentee provides an array of condenser coils within an enclosed condensate pan which is permanently mounted within the lower compressor to return moist air to the refrigeration compartment through an attached conduit.
A further early example may be found in U.S. Pat. No. 2,355,289 wherein the patentee provides a refrigerator unit in the form of a self-contained air conditioning unit which has a condensate collection pan surrounding the hot coil of a compressor. Hot compressed gas flowing through the coil causes evaporation of the condensate and the condensate is picked up by air flowing over the compressor and the pan of condensate.
A later example of such a prior art technique may be found in U.S. Pat. No. 4,783,971 wherein the patentees disclose a refrigeration device which includes a condensate collection pan mounted over an array of condenser coils. During a defrost cycle, the compressor is deactivated and a heating coil proximate to the evaporator is activated. The resulting water is drained to the drip pan where a fan circulates air across the drain pan to cool the condenser coil and evaporate the water in the pan.
This invention provides an improved condensate drain pan structure where the condensate will be quickly evaporated and where the drain pan itself is removable for cleaning. According to the present invention, a condensate collection structure includes a mounted bracket assembly that supports both a condenser tubing array and a removable condensate drain pan.
The bracket assembly is fixed to the bottom cabinet of a refrigerator or freezer unit by being cantilevered from a vertical wall thereof and supports a length of condenser tubing. The tubing may be wound in a serpentine manner to form a planar rectangular horizontal array. When a condensate drain pan is attached to the bracket assembly, the condenser tubing array fits down into and extends adjacent to the bottom of the drain pan. The condensate drain pan collects the condensate from the evaporator as it is heated during a defrost cycle. The liquid condensate collected in the condensate drain pan is evaporated out of the pan as it is heated by the condenser tubing during a refrigerator cycle. The condensate drain pan can be removed for cleaning by detaching the drain pan from the bracket assembly and then sliding the drain pan from underneath the condenser tubing array. The cantilevered mounting arrangement for the condenser tubing and the condensate pan eliminates complex mounting arrangements present in the prior art which increase assembly and repair costs.